St. Augustine Grass
Stenotaphrum secundatum · Warm-season, Perennial, C4 grass
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Lawn/Turf Grass
Variety / Cultivar
Common St. Augustine (likely non-dwarf, based on blade width and upward growth seen)
Hardiness Zones
USDA Zones 8-11. Poor cold tolerance; enters dormant brown state when temperatures consistently drop below 55°F; can be killed by hard freezes.
About This Grass
A coarse-textured, low-growing grass with a vibrant medium-to-dark green color. It forms a thick carpet that crowds out most weeds. If let go, it can grow 6-12 inches tall, producing a spike-like inflorescence where the seeds are embedded in the rachis.
Blade Characteristics
Wide (coarse, 8-10mm), flat blades with a distinct rounded or 'boat-shaped' tip. Vernation is folded in the bud. Color is medium green. Ligule is a fringe of short hairs; auricles are absent; the collar is broad and conspicuous.
Root System
Moderately deep fibrous root system originating from stolon nodes. It has a high thatch-forming tendency due to its thick stolons. Establishment is moderately fast via sod or plugs, but not available by seed.
Growing Information
Origin Region
Native to the coastal regions of the Gulf of Mexico, Caribbean, and Western Africa; well-adapted to USDA zones 8-11
Growth Habit
Stoloniferous; spreads aggressively via thick, creeping above-ground runners (stolons) to form a dense, coarse-textured mat
Sunlight & Water Needs
Full sun to partial shade; it is one of the most shade-tolerant warm-season grasses. Needs 4-6 hours of sun. Requires moderate to high watering; poor drought tolerance compared to Bermuda grass.
Mowing & Maintenance
Recommended height: 2.5 to 4.0 inches. Mowing frequency: Weekly during growing season. Fertilizer: 2-4 lbs N per 1000 sq ft annually. High maintenance level due to water and pest needs.
Special Characteristics
Excellent shade tolerance for a warm-season grass; high salt tolerance (ideal for coastal climates); low traffic tolerance due to the fleshy nature of the stolons which can be easily crushed.
Ecological Information
Introduced/Naturalized in the Southern US. Provides soil stabilization in sandy coastal areas. Noted for being susceptible to Chinch Bugs and Large Patch disease. Often found mixed with broadleaf weeds like the Dichondra and Pennywort seen in the image.